(Not Applicable)
(Not Applicable)
1. Field of Invention
This invention is directed to a method and an apparatus to obtain security tag operation using a local magnetic marker. In other words, a security tag is operational being able to respond to an interrogation signal clarifying the unpaid condition, as well as to monitor the environmental change local to a merchandise package, thereby reporting other offensive conditions such as package intrusion, distortion, violation, damaging, etc.
2. Prior Art
Today security tags are commonly used in retail stores and in supermarkets protecting merchandise against unauthorized removal. The conventional method involves the detection of the magnetization state of a magnetic tag attached to a commercial item seeking for protection. If the item has been properly checked out via a store clerk, the tag will be demagnetized at the cashier desk so as not to arouse an alarm installed near the doorway of the exit. However, if the item is carried out sneakingly without passing through the required checkout procedure, the alarm will be activated, identifying an unpaid item at the doorway.
The most serious drawback of the prior art is that there is no way to clarify an unpaid item at the doorway whose equipped security tag has already been removed or deactivated before exiting. To facilitate the checkout procedure at the cashier desk, the tag is normally attached to the merchandise at a prominent position unconcealed from the outside so that demagnetization of the tag can be conveniently carried out upon paying off. This offers opportunities for the burglar, and the burglar can readily peel off the tag with hands, or cut out the tag by using a razor blade, rendering the merchandise totally unprotected at the doorway exit.
To prevent the aforementioned situations to occur, the prior art dictates the tag to be wrapped around inside a thick plastic case or box which can not easily be opened or cut in a hurry. This increases the cost of the merchandise. The plastic box is transparent to human eyes and hence it will not impede the required checkout procedure at the cashier desk, but to add difficulty against unauthorized removal of the tag. However, even so, the burglar can still deactivate the tag by demagnetizing the tag using a permanent magnet, in as much as the same way that the store clerk is proceeding at the cashier desk during a normal checkout. By using a rare-earth metal permanent magnet, the magnet takes a volume less than 1 cm3, and hence this covert action can hardly be noticed in the store. To an experienced burglar, the easiest way to steal a commercial item under tag protection is to place the item as a whole inside a briefcase or a purse whose interior has been installed in advance with a thin soft-magnetic metal sheet, such as iron, nickel, cobol, or their alloys. Stealing in this way occurs in just seconds, and the alarm system can never be aroused, since the interrogation signal has no way to penetrate across the soft-magnetic metal sheet to reach the tag, and so does the responding signal from the tag to reach the detector. This process is called magnetic screening in the literature.
Some other annoying behaviors of the customers are that they enjoy to open a well-packaged merchandise to look at its inside without an intention to buy, some for curiosity, some for fun, and some for the purpose of steeling its parts, such as the enclosed manual, software, and so forth. A merchandise with its original package damaged can hardly be sold at a regular price, resulting in loss of the retail store or the supermarket. Again, the conventional security-tag system contained in the art has no way to guard against these offensive situations, and indeed new method and apparatus are in need.
Accordingly, it is an object of the invention to address one or more of the foregoing disadvantages or drawbacks of the prior art, and to provide such an improved method and apparatus to obtain security tag operation with added protection and performance coverage. That is, the disclosed method and apparatus lead to a tag system which can not only respond to an interrogation signal in as much as the same way that a conventional tag system does, but also it is able to guard against those offensive situations that a merchandise is liable to be damaged by a customer. It is almost impossible to remove or deactivate the tag system equipped with the merchandise without knowing the secret code, or password, which is required by the demagnetizing process. The tag will guard against the screening condition too, and hence the protection is nearly 100%. Most importantly, the disclosed security-tag system is convenient in use with high accuracy, as compact in size as the conventional system, but costs less. The detection scheme is simpler, and hence false alarms are less frequent, if not totally inhibited.
Other objects will be apparent to one of ordinary skill, in light of the following disclosure, including the claims.
In one aspect, the invention provides a method which sets up a security tag system via establishing a local relatively fixed magnetic environment using a magnetic marker. Any disturbance to this local-field environment can be readily checked, with a purpose not only to prevent the tag system from unauthorized removal, but also to guard against those offensive situations leading to merchandise damage. The tag system will respond to an interrogation signal if not being properly checked out. To deactivate the system, a password is required, which can not be obtained by a burglar. A second tag can be simultaneously applied to the system to detect the null condition, indicating the tag has been concealed in a screening sheet. The tag system is thus 100% secure providing full protection over a commercial merchandise.
In another aspect, the invention provides an apparatus which requires, in addition to a local magnetic marker, several units to constitute on-site guard electronics. The marker is furnished by a permanent magnet which is located at a hidden site. Depending on the size of the merchandise and the scope of protection, the size of the marker varies. The guard electronics includes a sensor unit capable of distinguishing 3 levels of an exposed magnetic field with sufficient resolution, corresponding to a local field, an interrogation field, and a reset field. Once recognized the exposed magnetic field, the microprocessor unit starts to function, taking necessary actions in response, either to ring a buzzer, to arouse an alarm, or to reset the electronics. While the marker will dispense with the merchandise after sale, the on-site guard electronics will be retrieved back to be reused with a new merchandise, thereby keeping the cost of the tag system at a minimum. The on-site guard electronics is encapsulated in a small stainless steel case assuming a minimum volume, which is mechanically hard to prevent against being damaged on purpose.